Analysis of Preimplantation and Clinical Outcomes of Two Cases by Oxford Nanopore Sequencing.

It is challenging to distinguish embryos with a balanced translocation karyotype from a normal karyotype by existing conventional genetic testing methods. However, in germ-cell gamete generation, chromosome exchange and separation through cell meiosis form a different proportion of unbalanced gametes. Adverse birth events may occur, such as repeated miscarriages and fetal birth defects. In this study, the exact breakpoints of structural variation (SV) from two balanced translocation carrier families by using Nanopore long reads sequencing technology were obtained, and haplotype analysis and Sanger verified the accuracy of the detection results, confirming the application value of the Nanopore sequencing technology in the detection of balanced translocation before embryo implantation. Nanopore long-read sequencing was performed to find the precise breakpoint of chromosome-balanced translocation carriers. The breakpoints were subsequently verified by designing primers across the breakpoints and Sanger sequencing. Haplotype linkage analysis of SNPs which can be linked by a read block of families around the breakpoint regions was followed. After frozen (-thawed) embryo transfer (FET), prenatal cytogenetic analysis of amniotic fluid cells confirmed the predicted karyotypes from the transferred embryos. The presence of breakpoints was detected in three embryos of patient 1. No breakpoints were detected in either embryo of patient 2. One balanced translocated embryo from patient 1 and one normal euploid embryo from patient 2 were transplanted back into the patients, and amniotic fluid cells were analyzed for the karyotype of fetuses. The results were entirely consistent with the fetal karyotype. And through late follow-up, both patients successfully had a live birth fetus. The breakpoint location of the balanced chromosome translocation can be accurately found by Nanopore sequencing. The haplotype of carriers can be successfully constructed by Nanopore and sanger sequencing confirmed that the results were accurate. This is very advantageous for preimplantation genetic testing for chromosomal structural rearrangements (PGT-SR) detection in the families without proband.

Engineering Hydroxylase Activity, Selectivity, and Stability for a Scalable Concise Synthesis of a Key Intermediate to Belzutifan.

Biocatalytic oxidations are an emerging technology for selective C-H bond activation. While promising for a range of selective oxidations, practical use of enzymes catalyzing aerobic hydroxylation is presently limited by their substrate scope and stability under industrially relevant conditions. Here, we report the engineering and practical application of a non-heme iron and α-ketoglutarate-dependent dioxygenase for the direct stereo- and regio-selective hydroxylation of a non-native fluoroindanone en route to the oncology treatment belzutifan, replacing a five-step chemical synthesis with a direct enantioselective hydroxylation. Mechanistic studies indicated that formation of the desired product was limited by enzyme stability and product overoxidation, with these properties subsequently improved by directed evolution, yielding a biocatalyst capable of >15,000 total turnovers. Highlighting the industrial utility of this biocatalyst, the high-yielding, green, and efficient oxidation was demonstrated at kilogram scale for the synthesis of belzutifan.

Acarbose reduces Pseudomonas aeruginosa respiratory tract infection in type 2 diabetic mice.

BACKGROUND: Type 2 diabetes mellitus (T2DM) is widely prevalent worldwide, and respiratory tract infections (RTIs) have become the primary cause of death for T2DM patients who develop concurrent infections. Among these, Pseudomonas aeruginosa infection has been found to exhibit a high mortality rate and poor prognosis and is frequently observed in bacterial infections that are concurrent with COVID-19. Studies have suggested that acarbose can be used to treat T2DM and reduce inflammation. Our objective was to explore the effect of acarbose on P. aeruginosa RTI in T2DM individuals and elucidate its underlying mechanism. METHODS: High-fat diet (HFD) induction and P. aeruginosa inhalation were used to establish a RTI model in T2DM mice. The effect and mechanism of acarbose administered by gavage on P. aeruginosa RTI were investigated in T2DM and nondiabetic mice using survival curves, pathological examination, and transcriptomics. RESULTS: We found that P. aeruginosa RTI was more severe in T2DM mice than in nondiabetic individuals, which could be attributed to the activation of the NF-κB and TREM-1 signaling pathways. When acarbose alleviated P. aeruginosa RTI in T2DM mice, both HIF-1α and NF-κB signaling pathways were inhibited. Furthermore, inhibition of the calcium ion signaling pathway and NF-κB signaling pathway contributed to the attenuation of P. aeruginosa RTI by acarbose in nondiabetic mice. CONCLUSIONS: This study confirmed the attenuating effect of acarbose on P. aeruginosa RTIs in T2DM and nondiabetic mice and investigated its mechanism, providing novel support for its clinical application in related diseases.

Construction of a type-II BiVO4/BiOI heterojunction for efficient photoelectrocatalytic degradation of ß-naphthol and coal gasification wastewater under visible-light irradiation.

Herein, a novel type-II BiVO4/BiOI (BVOI) heterojunction electrode material was successfully fabricated by using a facile two-step electrodeposition approach. The experimental results revealed that BiOI nanosheets were deposited onto the surface of BiVO4 particles successfully, with the special morphology providing more active sites, which was beneficial to the improvement of PEC performance. According to the electrochemical performance tests, it could be observed that the construction of a heterojunction effectively promoted the separation of photoinduced electron-hole pairs and increased the transfer rate of surface charges. Under visible-light irradiation, the BVOI-300 photoanode possessed the highest PEC ß-naphthol degradation rate at pH = 7, which approximately reached 82%, whose corresponding kinetic constant was 1.4 and 1.5 times higher than those of pure BiVO4 and BiOI. After five cycles, the degradation rate still remained at 64.61%. The band structure of the BVOI electrode was deduced, and the PEC mechanism of the BVOI electrode was investigated through the radical trapping quenching experiments and ESR test, which indicated that the ˙OH, h+ and ˙O2- radicals were crucial active species in the PEC ß-naphthol degradation process. For the BVOI-300 working electrode, the TOC content of coal gasification wastewater (CGW) decreased from 94.44 to 54.4 mg L-1, and the removal rate reached 42.4%. GC-MS was used to identify the organic components of coal gasification wastewater, which was expected to provide reference for remedying actual gasification wastewater containing refractory organic pollutants and offer a new development direction for the treatment of actual coal chemical wastewater.

Combined Silver Sulfadiazine Nanosuspension with Thermosensitive Hydrogel: An Effective Antibacterial Treatment for Wound Healing in an Animal Model.

Introduction: Silver sulfadiazine (AgSD) is widely used in burn wound treatment due to its broad-spectrum antibacterial activity. However, its application in wound healing is greatly hindered by the low solubility of AgSD particles and their cellular cytotoxicity. Herein, we studied the safety and in vivo efficacy of nano-sized silver sulfadiazine loaded in poloxamer thermosensitive hydrogel (NS/Gel). Methods: In NS/Gel, silver sulfadiazine was prepared into silver sulfadiazine nanosuspension (NS) to improve the solubility and enhance its antibacterial activity, whereas the poloxamer thermosensitive hydrogel was selected as a drug carrier of NS to achieve slow drug release and reduced cytotoxicity. The acute toxicity of silver sulfadiazine nanosuspension was first evaluated in healthy mice, and its median lethal dose (LD50) was calculated by the modified Karber method. Furthermore, in vivo antibacterial effect and wound healing property of NS/Gel were evaluated on the infected deep second-degree burn wound mice model. Results: The mortality ratio of mice was concentration-dependent, and the LD50 for silver sulfadiazine nanosuspension was estimated to be 252.1 mg/kg (230.8 to 275.4 mg/kg, 95% confidence limit). The in vivo dosages used for burn wound treatment (40-50 mg/kg) were far below LD50 (252.1 mg/kg). NS/Gel significantly accelerated wound healing in the deep second wound infection mice model, achieving > 85% wound contraction on day 14. Staphylococcus aureus in the wound region was eradicated after 7 days in NS/Gel group, while the bacterial colony count was still measurable in the control group. Histological analysis and cytokines measurement confirmed that the mice treated with NS/Gel exhibited well-organized epithelium and multiple keratinized cell layers compared to control groups with the modulated expression of IL-6, VEGF, and TGF-ß. Conclusion: The combination of silver sulfadiazine nanosuspension and thermo-responsive hydrogel has great potential in clinical burn wound treatment.

Surgical outcomes of two different reconstruction routes for esophagectomy in esophageal cancer patients: a meta-analysis.

To evaluate the effects of two different reconstruction routes (the posterior mediastinal route (PR) and the retrosternal route (RR)) on the surgical outcomes of patients after esophagectomy for esophageal carcinoma. PubMed, Embase, Web of Science and Scopus were searched from database inception to March 2021. Randomized controlled trials (RCTs) and case-control trials on the surgical outcomes of patients undergoing esophagectomy via one of the two routes were included. RevMan 5.3 software was used for the meta-analysis. In total, 19 studies were included, 8 were RCTs and 11 were case-control studies. The meta-analysis showed that among the case-control trials, the PR had reduced rates of anastomotic leakage [odds ratio (OR) = 0.56, 95% confidence interval (CI) (0.43, 0.74), P < 0.01]. In addition, it had reduced rates of anastomotic stenosis [OR = 0.42, 95% CI (0.30, 0.59), P < 0.01] and pulmonary complications [OR = 0.63, 95% CI (0.47, 0.84), P < 0.01]. However, there was no significant difference in cardiac complications [RCTs, relative risk (RR) = 0.57, 95% CI (0.29, 1.11), P = 0.10; case-control trials, OR = 1.06, 95% CI (0.70, 1.62), P = 0.78] or postoperative mortality [RCTs, RR = 0.47, 95% CI (0.19, 1.16), P = 0.10; case-control trials, OR = 0.68, 95% CI (0.32, 1.44), P = 0.31]. Compared with the RR, the PR had reduced rates of anastomotic leakage, anastomotic stenosis and pulmonary complications.

Comparison of single-port vs. two-port VATS technique for primary spontaneous pneumothorax.

BACKGROUND: Video-assisted thoracoscopic surgery (VATS) has been used for thoracic surgery for about two decades. As the trend in VATS is to use fewer ports to decrease postoperative complications, we compared the results of our experience with single-port and two-port VATS for primary spontaneous pneumothorax (PSP). MATERIAL AND METHODS: This is a non-randomized retrospective study. From January 2017 to December 2018, 104 patients with PSP underwent VATS. Fifty-six patients received single-port VATS and 48 patients received two-port VATS. Operation time, blood loss, number of staplers used, drainage time, postoperative hospital stay, complications, chest wall paresthesia, visual analog scale (VAS) pain scores, and patient satisfaction scale scores were compared between the two groups. RESULTS: There was no difference in age, gender, body mass index (BMI), smoking status, surgical indication, and involved side between the two groups. The procedures performed in the single-port group were similar to those performed in the two-port group. No significant difference was found in operation time, blood loss, number of staplers used, drainage time, and recurrence rate. The rate of chest wall paresthesia was lower in the single-port group than in the two-port group (28.6 vs. 52.1%, p = .014). The VAS scores in the single-port group were lower than those in the two-port group at 24 and 48 h (p = .032 and p = .004). CONCLUSIONS: Compared with two-port VATS, single-port VATS for PSP showed more favorable results in terms of postoperative paresthesia and pain. The single-port procedure may be considered a good alternative to the standard thoracoscopic treatment of PSP. Abbreviations: VATS: Video-assisted thoracic surgery; PSP: primary spontaneous pneumothorax.

Magnetic graphene-based nanocomposites as highly efficient absorbents for Cr(VI) removal from wastewater.

Due to the merits of their high adsorption and convenient separation, magnetic graphene-based composites have become a promising adsorbent in terms of wastewater treatment. However, recycling and regeneration properties of magnetic graphene-based composites are still a conundrum, which remains to be resolved. Here, Fe3O4/reduced graphene oxide (RGO) (Fe3O4/RGO) nanocomposites were synthesized by one-step solvent-thermal reduction route and used as adsorbents for water purification. It was encouraging to find that the nanocomposites possessed many intriguing properties in removing of Cr(VI) ions, including high adsorption efficiency and excellent recycling and regeneration property. The results indicated that the magnetic separation process of the Fe3O4/RGO nanocomposites only took less than 5 s and the maximum removal efficiency of Cr(VI) reached 99.9% under the optimum experimental conditions. Most significantly, the adsorption rate of Cr(VI) can still be as high as 98.13% after 10 cycles and the single recycle quality of the nanocomposites can maintain at more than 80%. As a result, the Fe3O4/RGO nanocomposites could be a potential adsorbent for removing heavy metal ions effectively, especially in environmental protection and restoration.

A minireview on doped carbon dots for photocatalytic and electrocatalytic applications.

To date, carbon dots (CDs) or carbon quantum dots (CQDs), considered as alternatives to conventional fluorescent materials such as organic dyes and semiconductor quantum dots (QDs), have drawn significant attention from relevant researchers due to their superior properties, including nontoxicity, biocompatibility, low cost and facile synthesis, and high photoluminescence. In particular, doping heteroatoms with CDs can not only dramatically enhance the fluorescence but also greatly improve the electronic structure and doped CDs have been successfully applied in various technological fields. Herein, this minireview summarizes recent advances on the synthesis and optical properties of doped CDs and their promising applications for photocatalysis and electrocatalysis. Finally, some challenging issues as well as future perspectives of this exciting material are discussed.

A multifaceted biomimetic interface to improve the longevity of orthopedic implants.

The rise of additive manufacturing has provided a paradigm shift in the fabrication of precise, patient-specific implants that replicate the physical properties of native bone. However, eliciting an optimal biological response from such materials for rapid bone integration remains a challenge. Here we propose for the first time a one-step ion-assisted plasma polymerization process to create bio-functional 3D printed titanium (Ti) implants that offer rapid bone integration. Using selective laser melting, porous Ti implants with enhanced bone-mimicking mechanical properties were fabricated. The implants were functionalized uniformly with a highly reactive, radical-rich polymeric coating generated using a unique combination of plasma polymerization and plasma immersion ion implantation. We demonstrated the performance of such activated Ti implants with a focus on the coating's homogeneity, stability, and biological functionality. It was shown that the optimized coating was highly robust and possessed superb physico-chemical stability in a corrosive physiological solution. The plasma activated coating was cytocompatible and non-immunogenic; and through its high reactivity, it allowed for easy, one-step covalent immobilization of functional biomolecules in the absence of solvents or chemicals. The activated Ti implants bio-functionalized with bone morphogenetic protein 2 (BMP-2) showed a reduced protein desorption and a more sustained osteoblast response both in vitro and in vivo compared to implants modified through conventional physisorption of BMP-2. The versatile new approach presented here will enable the development of bio-functionalized additively manufactured implants that are patient-specific and offer improved integration with host tissue. STATEMENT OF SIGNIFICANCE: Additive manufacturing has revolutionized the fabrication of patient-specific orthopedic implants. Although such 3D printed implants can show desirable mechanical and mass transport properties, they often require surface bio-functionalities to enable control over the biological response. Surface covalent immobilization of bioactive molecules is a viable approach to achieve this. Here we report the development of additively manufactured titanium implants that precisely replicate the physical properties of native bone and are bio-functionalized in a simple, reagent-free step. Our results show that covalent attachment of bone-related growth factors through ion-assisted plasma polymerized interlayers circumvents their desorption in physiological solution and significantly improves the bone induction by the implants both in vitro and in vivo.

Hydrothermal-template synthesis and electrochemical properties of Co3O4/nitrogen-doped hemisphere-porous graphene composites with 3D heterogeneous structure.

Despite the high capacity of Co3O4 employed in lithium-ion battery anodes, the reduced conductivity and grievous volume change of Co3O4 during long cycling of insertion/extraction of lithium-ions remain a challenge. Herein, an optimized nanocomposite, Co3O4/nitrogen-doped hemisphere-porous graphene composite (Co3O4/N-HPGC), is synthesized by a facile hydrothermal-template approach with polystyrene (PS) microspheres as a template. The characterization results demonstrate that Co3O4 nanoparticles are densely anchored onto graphene layers, nitrogen elements are successfully introduced by carbamide and the nanocomposites maintain the hemispherical porous structure. As an anode material for lithium-ion batteries, the composite material not only maintains a relatively high lithium storage capacity (the first discharge specific capacity can reach 2696 mA h g-1), but also shows significantly improved rate performance (1188 mA h g-1 at 0.1 A g-1, 344 mA h g-1 at 5 A g-1) and enhanced cycling stability (683 mA h g-1 after 500 cycles at 1 A g-1). The enhanced electrochemical properties of Co3O4/N-HPGC nanocomposites can be ascribed to the synergistic effects of Co3O4 nanoparticles, novel hierarchical structure with hemisphere-pores and nitrogen-containing functional groups of the nanomaterials. Therefore, the developed strategy can be extended as a universal and scalable approach for integrating various metal oxides into graphene-based materials for energy storage and conversion applications.

Investigation on the orientation dependence of elastic response in Gyroid cellular structures.

Materials used for hard tissue replacement should match the elastic properties of human bone tissue. Therefore, cellular structures are more favourable for the use of implants than solid materials for their custom-designed mechanical properties. The superimposed load from various directions in vivo makes uniaxial compression testing insufficient for describing the mechanical responses. In this paper, the rotational symmetry of Gyroid cellular structure (GCS) was discussed. An approach using structural simplification and analytical solution was presented to investigate the relationship between Young's modulus and volume fraction, as well as the orientation dependence of the mechanical responses for GCS loaded in various orientations. It is concluded that the analytical solution is reasonable for a low volume fraction, through the comparison between analytical results, finite element (FE) and experimental data. Gained polar diagrams illustrate the anisotropic property of GCS and also confirm the superiority for their stable mechanical responses of diverse loading directions.

Serum microRNA-139-5p is downregulated in lung cancer patients with lytic bone metastasis.

Bone remodeling can be interrupted by tumor cells which leads to an inappropriate balance of osteoblasts and osteoclasts. As the progenitors of osteoblasts, mesenchymal stem cells (MSCs) have been reported to exhibit an abnormal osteogenic differentiation potential in some cancer­related bone lesions. However, the evidence is very limited in terms of the biological alterations of MSCs in the bone metastasis of non­small cell lung cancers (NSCLC). We investigated the expression and function of miR­139­5p in MSC osteogenic differentiation in vitro in normal and NSCLC-exposed condition. Then, we compared the serum miR­139­5p in stage IV lung adenocarcinoma cancer patients with and without lytic bone metastasis. We found that MSCs exhibited a significant increase in miR­139­5p expression after exposure to osteogenic differentiation induction medium. However, Notch1, which was confirmed as a target of miR­139­5p by luciferase and western blot assays, showed a marked downregulated expression together with its pathway downstream factors during MSC osteogenesis. miR­139­5p positively regulated MSC osteogenic differentiation but this effect was abrogated significantly by Notch1 knockdown. After exposure to conditions of lung cancer cells A549 and L9981, MSCs exhibited significant downregulation of miR­139­5p expression and early osteogenic marker ALP activity. Furthermore, we demonstrated that the expression of serum miR­139­5p from lung adenocarcinoma patients with lytic bone metastasis was significantly lower compared to that in patients with metastases in other organs. The potential roles of miR­139­5p as a biomarker and treatment target in monitoring and controlling bone metastasis in lung cancer patients are worthy of being further explored.

Primary pulmonary malignant fibrous histiocytoma: case report and literature review.

Malignant fibrous histiocytoma (MFH) is an aggressive soft tissue sarcoma known to occur in various organs. Primary MFH arising in the lung is quite rare. Herein we report a case of a 61-year-old male with primary pulmonary MFH and explore the underlying molecular mechanisms by next-generation sequencing (NGS). Five gene mutations in TSC2, ARID1B, CDK8, KDM5C and CASP8 were detected, and the mTOR inhibitor might be an effective treatment for this patient. In addition, we reviewed the scientific literature of approximately 23 primary pulmonary MFH case reports since 1990 and summarized the clinical features and prognosis of this rare pulmonary malignant tumor.

Characterization of a novel nitrilase, BGC4, from Paraburkholderia graminis showing wide-spectrum substrate specificity, a potential versatile biocatalyst for the degradation of nitriles.

OBJECTIVE: To investigate the biodegradation of nitriles via the nitrilase-mediated pathway. RESULTS: A novel nitrilase, BGC4, was identified from proteobacteria Paraburkholderia graminis CD41M and its potential for use in biodegradation of toxic nitriles in industrial effluents was studied. BGC4 was overexpressed in Escherichia coli BL21 (DE3), the recombinant protein was purified and its enzymatic properties analysed. Maximum activity of BGC4 nitrilase was at 30 °C and pH 7.6. BGC4 has a broad substrate activity towards aliphatic, heterocyclic, and aromatic nitriles, as well as arylacetonitriles. Iminodiacetonitrile, an aliphatic nitrile, was the optimal substrate but comparable activities were also observed with phenylacetonitrile and indole-3-acetonitrile. BGC4-expressing cells degraded industrial nitriles, such as acrylonitrile, adiponitrile, benzonitrile, mandelonitrile, and 3-cyanopyridine, showing good tolerance and conversion rates. CONCLUSION: BGC4 nitrilase has wide-spectrum substrate specificity and is suitable for efficient biodegradation of toxic nitriles.

A novel nitrilase from Ralstonia eutropha H16 and its application to nicotinic acid production.

A novel aliphatic nitrilase, REH16, was found in Ralstonia eutropha H16 and overexpressed in Escherichia coli BL21(DE3), and its enzymatic properties were studied. The temperature and pH optima were 37 °C and 6.6, respectively, and the best thermostability of the nitrilase was observed at 25 °C, which preserved 95% of activity after 120 h of incubation. REH16 has a broad hydrolytic activity toward aliphatic and heterocyclic nitriles and showed high tolerance of 3-cyanopyridine; this enzyme could hydrolyze as high as 100 mM 3-cyanopyridine completely. To improve the 3-cyanopyridine conversion efficiency in an aqueous reaction system, water-miscible organic solvents were tested, and ethanol (10% v/v) was chosen as the optimal co-solvent. Finally, under optimized conditions, using the fed-batch reaction mode, total of 1050 mM 3-cyanopyridine was hydrolyzed completely in 20.8 h with eight substrate feedings, yielding 129.2 g/L production of nicotinic acid and thus showing a potential for industrial application.

Enhancement of ethyl (S)-4-chloro-3-hydroxybutanoate production at high substrate concentration by in situ resin adsorption.

Asymmetric reduction of ethyl 4-chloro-3-oxobutyrate (COBE) by carbonyl reductases presents an efficient way to produce Ethyl (S)-4-chloro-3-hydroxybutanoate ((S)-CHBE), an important chiral intermediate for the synthesis of hydroxymethylglutaryl-CoA reductase inhibitors such as Lipitor®. In this study, an NADPH-dependent carbonyl reductase (SrCR) from Synechocystis sp. was characterized to demonstrate a broad substrate spectrum, and the highest activity (53.1U/mg protein) with COBE. To regenerate the cofactor NADPH, Bacillus subtilis glucose dehydrogenase was successfully coexpressed with SrCR. Owing to the product inhibition, no more than 400mM of COBE could be completely reduced to (S)-CHBE using the recombinant Escherichia coli/pET-SrCR-GDH. The macroporous adsorption resin HZ 814 was applied to adsorb (S)-CHBE in situ to alleviate the product inhibitio. Consequently, 3000mM (494g/L) of COBE was bioconverted within 8h, resulting in a (S)-CHBE yield of 98.2%, with 99.4% ee and total turnover number of 15,000, revealed great industrial potential of (S)-CHBE production.

[T-peptide Enhances the Killing Effects of Cisplatinum on Lung Cancer].

BACKGROUND: T peptide is extensively used in anti-tumor treatment. The aims of this study were to investigate whether T peptide enhances cisplatinum efficiency while reducing its side effects and to identify its effective mechanisms. METHODS: (1) Human macrophage U937 cells were treated with T peptide and/or cisplatinum. The levels of tumor necrosis factor-α (TNF-α) and interferon-γ (IFN-γ) of each group were detected by enzyme-linked immunosorbent assay (ELISA); (2) Xenograft mouse models of human lung cancer were treated with T peptide and/or cisplatinum once every five days for three times. Tumor volumes were measured during treatment; (3) The percentages of macrophages in the peripheral blood of the xenograft mouse models were measured by FACS. RESULTS: (1) Compared with other groups, the level of TNF-α was significantly higher in the human macrophage U937 cells that were treated with T peptide combined with cisplatinum. The levels of IFN-γ were significantly higher in human macrophage U937 cells that were treated with T peptide alone or T peptide combined with cisplatinum; (2) In the xenograft mouse models, T peptide combined with cisplatinum treatment significantly inhibited tumor growth without weight loss compared with the other groups; (3) The percentages of macrophages in the peripheral blood were significantly higher in the xenograft mouse models that were treated with T peptide combined with cisplatinum compared with in the other groups. CONCLUSIONS: T peptide promotes macrophage proliferation and increases tumor cell killing factors (TNF-α, IFN-γ) in vitro. Moreover, T peptide enhances the efficacy of cisplatin and reduces its toxicity in vivo.
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[Expression and Clinical Significance of PD-1 and PD-L1 in Pulmonary Carcinoids].

BACKGROUND: The incidence of pulmonary carcinoid (PC) is very rare in primary lung malignant tumors, and the prognosis of this disease is closely associated with its pathological features. In this study, the expressions of programmed death 1 (PD-1) and programmed death ligand-1 (PD-L1) in lung carcinoid cells were detected, and the correlation between the expression and corresponding clinical physiological and pathologic features was further analyzed. METHODS: The expressions of PD-1 and PD-L1 in 20 cases of PC paraffin-embedded tissue specimens were detected through immunohistochemistry. The H-score of immunohistochemical staining (range, 0-300) was employed to evaluate the expression of PD-1 and PD-L1 in the tumor tissues. RESULTS: In the 20 cases of patients with PC, 40% (8/20) showed positive expressions of PD-1, and 45% (9/20) showed positive expressions of PD-L1. Significantly higher expressions of PD-1 were observed in the smoking patients than in the nonsmoking patients (63.64% vs 11.11%, P<0.05). Furthermore, no significant relationship was found between the expressions of PD-1 and PD-L1 and the clinical characteristics of the patients, such as age, gender, pathological type, clinical stage, and metastasis (P>0.05). CONCLUSIONS: Approximately 40% of PC patients had positive expressions of PD-1or PD-L1. The positive expression rate of PD-1 in the smoking patients was significantly higher than that in the nonsmoking patients. These results suggest that the expressions of PD-1 and PD-L1 may be associated with the occurrence and development of PC.

Practical two-step synthesis of enantiopure styrene oxide through an optimized chemoenzymatic approach.

Enantiopure styrene oxide (SO) and its derivatives are important building blocks for chiral synthesis. In this study, we developed an attractive "1-pot, 2-step" chemoenzymatic approach for producing enantiopure SO with 100 % theoretical yield. This approach involved asymmetric reduction of α-chloroacetophenone by an alcohol dehydrogenase (ADH; step 1), followed by base-induced ring closure (epoxidation) of enantiopure 2-chloro-1-phenylethanol produced by the ADH (step 2). By-product formation during epoxidation was suppressed to <1 % by adding methyl tert-butyl ether (MTBE) as the second phase. Therefore, with this optimized approach, ADH from Lactobacillus kefir (LkDH) successfully produced 1 M (S)-SO, with 99 % analytical yield and 97.8 % enantiomeric excess (ee). In the preparation of (R)-SO, a semi-rational strategy of active pocket iterative saturation mutagenesis (ISM) was successfully used to inverse the enantioselectivity of LkDH (muDH2, F147L/Y190P/A202F/M206H/V196L/S96D/K97V), which produced the opposite enantiomer (R)-2-chloro-1-phenylethanol. Through the optimized chemoenzymatic approach, muDH2 was successfully used to prepare 1 M (R)-SO, with 98.1 % ee and 99.0 % analytical yield. Our results indicated that this optimized chemoenzymatic approach could be used to produce both enantiomers of SO at concentrations as high as 120 g/L within 14 h, which is the highest concentration as far as we know. MuDH2 obtained through ISM also showed reversed enantioselectivity toward another 13 aromatic ketones, compared with wild-type (WT) LkDH. Furthermore, a molecular docking experiment demonstrated that muDH2 inverted the binding orientation of the substrate, which may be the reason for its inverse enantioselectivity.